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(No Model.) 7

H. LEMP 8c. M; J. WIGHTMAN. GUT-OUT FOR INUANDESGENT LAMPS.

No. 352,621. Patented Nov. 16, 1886.

m. wmm um D c UNITED STATES PATENT OEEIcE.

HERMANN LEMP AND MERLE J. NVIGHTMAN, OF HARTFORD, CONNECTICUT, ASSIGNORSTO THE SCHUYLER ELECTRIC LIGHT COMPANY.

CUT-OUT FOR INCANDESCENT LAMPS.

SPECIFICATION forming part of Letters Patent No, 352,621, dated November16, 1886.

Application filed August 19, 1886. Serial No. 211.32%. (No model.)

To aZZ whom it may concern:

Be it known that we, HERMANN LEMP and MERLE J. WrenrMAN, citizens of theUnited States, and residents of Hartford, in the State of Connecticut,have invented a certain new and useful Improved Cut-Ont for IncandescentLamps,of which the following is aspecification.

In the prior application for patent filed by us March 2, 1886, No.193,752, we have de- IO scribed an automatic electric cutout, designedmore especially for application to incandescent lamps, and based uponthe principle of the fusing action of an electric are or current,

which, on rupture of the lamp filament or other working resistance, ismade to involve parts forming or electrically connected with the twopoles of the lamp, which parts are so located with reference to eachother that the material fused by the are electrically unites 2O them,thus forming a short-circuiting joint.

In our prior application referred to the ,parts fused to form the jointare formed of a conducting metal-such as copperthe two poles of the lampconsisting, essentially, of

conductors brought into close proximity, so that the are in playing fromone to the other shall fuse one or both, and the molten metal shallunite the poles.

In another application for patent filed by us we employ a similarprinciple; but the material by whose i'usion a joint is formed consistsof a substance that is normally, or when cold, an insulator, but whichwhen heated or fused by the action of the arc is transformed into a 5.conducting material.

1n. the latter case the material forms the insulator, normallyseparating the two poles of the apparatus, and the electrical joint isin this instance ordinarily formed without fusion of the metal poles.

Our present invention relates to a means whereby the action of devicessuch as dc scribed in our prior applications may be rendered morecertain.

The invention consists, essentially, in the combination, with eachconductor or pole of the apparatus, of a conducting extension unitedtherewith and carried into proximity with but normally out of connectionwith the so other pole.

Our invention consists, further, in certain details of construction thatwill be described in connection with the accompanying drawingspand thenrecited in the claims.

NVe have described theinvention as applied 5 5 to an incandescent lamp,but do notlimit ourselves to such special application, although thedevices herein set forth are specially applicable and are speciallydesigned for application to incandescent lamps.

Referring to the accompanying drawings, Figure 1 is an elevation of apart of an iir candescentlamp, showing our invention ap plied thereto.Fig. 2is a cross-section on the line a: m, Fig. 1. Figs. 3 and 4 arerespectively a side elevation and a cross-section of a modification.Figs. 5 and 6 are similar views of another modification. Fig. 7 is a topview of the device shown in Fig. 4, showing the parts after fusion hastaken place so as to unite the two poles of the lamp independent] y ofthe filament or conductor.

Referring to Fig. 1, a b indicate the two entering or supportingconductors for an incandescent lamp. These conductors or poles are 7 5sealed and supported in any desirable manner. At 1) is indicated aconductor consisting of a sheet or band of copper which is electricallyunited with the pole b, and is wrapped around or is carried intoproximity with the other pole, as indicated. A similar conductor, a isunited with the pole a, and is carried into proximity with the pole b.The extensions thus formed from the two poles are insulated from oneanother by any suitable insulating material-such, for instance, as astrip of mica, d, which need be no thicker than onesixty-fourth of aninch, but is made somewhat wider than the two strips-s0 that thedistance from one pole-extension, I)", to the other poleextension, aaround the edge of the mica shall be the same as the distance laterallybetween the two upright conductors ab. As explained in our applicationfiled, theinsulator (mica) might be replaced by an insulator which by 95fusion would be reduced to a metallic or conducting slate.

In the operation of this device therupture of the filament orincandescent conductor, or

the opening of the circuit connecting the two poles a I) normally,results in the formation of an are which, traveling down the conductorsa b, finally envelops the polar extensions, and fusing them forms aconducting-joint. This is the assumed mode of operation, though in somecases it might happen that with a current of high potential the currentwill force its way directly across from one conductor, 5*, to the other,a and will in the same way fuse one or both, so that the melted metalwill electrically unite the two poles of the apparatus.

A more convenient way of making the device is illustrated in Figs. 3 and4. In this case we take two strips of copper or other ma terial madesufficiently thin to be pliable, and we attach or solder each strip toone of the conductors or poles a b. One of said strips is wrapped aroundone of the poles-as, for instance, aand the other is wrapped around pole1). Between the two strips is located a sheet of mica. Each strip isthen carried to the opposite pole and partially wrapped around it, thesheet of mica serving as the insulation, which keeps the two strips outof normal connection with one another, and respectively out of contactwith the two poles a I).

In Fig. 5 we have shown another niodification, in which, to avoiddangcrof the strips be coming detached, we make one of them much longer thanthe other, as shown, so that after they have been wrapped, after themanner illustrated in Fig. 4, the longer strip may be wrapped around thewhole mass several times, so as to form a retaining-band.

Fig. 7 illustrates in top view a form in which the device is sometimesleft after rupture of a filament and the production of a fused jointuniting the two poles of the lamp. As will be here seen, the joint isformed in proximity to both of the conductors a I), each ofsaidconductors itselfbeinginvolved through iusion in the formation ofajoint.

It is obvious that our invention may be carried out by using conductorsor conductingextensions formed in other ways instead of fromsheet-copper, and that other materials may be used in place of copper.

In applying our device to an incandescent lamp we locate the copperstrips or extensions within the vacuous space containing theincandescent conductor or other device.

W'hat we claim as our invention is 1. In an incandescent lamp, thecombination, with the enteringin conductors, of a conducting-extensionfrom each brought into proximity with, but normally insulated from, theother pole.

2. In an electric lamp, the combination, with the poles to b, of theconducting-extensions lapping one upon the other and connected each withone of the poles, but normally insulated from the other pole.

3. The combination, with the entering eonductors for an incandescentlamp, of two conducting-extensions electrically united with said poles,respectively, and each brought into proximity with, but normallyinsulated from, the opposite pole, as and for the purpose described. 4

at. In an automatic cut-out, the combination, with the conductors a b,of a wrapping composed of two superposed conductors normally insulatedfrom one another but connected, re spectively, with said conductors, asand for the purpose described.

5. The combination, with the entering supporting-conductors for anincandescent lamp, of conducting-extensions connected, respectively,with one of said conductors and brought into proximity with the other,said extensions being formed of two overlapping conductors wrappedaround the supporting-conductors of the lamp.

6. In an electric lamp, the combination, with the entering-inconductors, of two flexible con-' ducting-strips electrically unitedwith said conductors, respectively, and wrapped around the same, with aninterposed sheet ot'non-conducting material, as 'and for the purpose described.

7. In an electric lamp, the combination, with the two entering-inconductors a b, of two conducting-strips electrically connected withsaid conductors, respectively, and each wrapped around but insulatedfrom the opposite pole or conductor.

8. In an eleetriclamp, the combination, with the entering-in conductorsa. b, of the two flexible enveloping-strips connected, respectively,with the conductors a b, but insulated from one another, one of saidstrips being made longer than the other to form an exterior wrapping.

Signed at Hartford, in the county of Hartford aud State of Connecticut,this 28th day of July, A. D. 1886.

. H ERMANN LEMP.

MERLE J. XVIGHTMAN. \Vitnesses:

CHAS. A. KELLOGG, A. GRAY KILBOURNE.

